meter-, metro-, metr-, -metrical, -metrically, -metron, -metric, -metrist, -meters, -metry, -metre

1. The science of measuring physical characteristics, to verify a person’s identity which includes voice recognition, iris and face scans, and fingerprint recognition.

This definition is a recent application from the tech world [a recently created application]. This sense of biometrics should not be confused with the much older sense, which refers to the application of statistical and mathematical methods for data analysis in the biological sciences. Also known as biometry (as shown in the next word group), this use of the term has been in the language since the early 1900s.

2. Quantification of psychopathological differences between subjects, specifically by assessing each subject across multiple dimensions. In psychiatry, those dimensions include sensation, perception, cognition, learning, psychophysiological reactions, and personality traits and characteristics.

More info about the science of biometrics.

1. The application of statistical methods to the study of numerical data based on biological observations and phenomena.
2. The measurement of life; the calculation of the average duration and expectation of life.
3. The application of mathematics to biology; especially, the study of resemblances between living things by statistical methods.
4. In the field of life insurance, the calculation of life expectancy.

An obsolete instrument once used for measuring the rate and degree of dark adaptation, as in vitamin "A" deficiency.

Spectroscopic determination of the types and amounts of various substances in living tissue or fluid from a living body.

1. Study of the behavior and activity of organisms using remote detection and transmission equipment; radio tracking.
2. The technique of monitoring vital processes and transmitting data without wires to a point remote from the subject.
3. The tracking of a free-ranging animal, or the monitoring of one or more of its physiological conditions, by beans of electronic equipment that receives signals from a radio transmitter or similar device attached to, or embedded in the animal.

An instrument for measuring the vibratory-perception threshold.

A device, or instrument, for measuring the intensity of thunder.

An instrument for determining the amount of butterfat in milk.

Measuring bad air.

The science of measuring the concentration of smoke in the atmosphere, in a smoke plume, or in a flue gas.